Prognostic value of pretreatment temporal muscle thickness after curative surgery for oral cavity squamous cell carcinoma.

BACKGROUND: Sarcopenia is a poor prognostic factor in various diseases. Temporal muscle thickness (TMT) has been reported to be associated with sarcopenia. We investigated the prognostic value of TMT in patients with oral squamous cell carcinoma. METHODS: This study included 61 patients with oral squamous cell carcinoma. Two board-certified otolaryngologists measured TMT based on pre-treatment CT. The following sex-specific TMT cut-off values were used in accordance with previous reports: ≤ 6.3 mm in men, and ≤ 5.2 mm in women. We classified patients into normal TMT group and low TMT group according to the cutoff values. The correlation between the TMT measurements of the two readers was tested using the interclass correlation coefficient (ICC). Cox regression models were used to verify the association between TMT and prognostic factors. RESULTS: The low TMT group had a significantly lower BMI than the normal TMT group. Patients with low TMT at baseline had a significantly higher risk of death than those with normal TMT (hazard ratio 4.51; 95% confidence interval [CI] 1.49-13.61; p = 0.0076). There were no significant differences in disease-specific survival between the two groups. The correlation between the two evaluators' TMT measurements was excellent (ICC 0.988, 95% CI 0.981-0.933). CONCLUSIONS: Sex-specific TMT was associated with overall survival in patients with oral squamous cell carcinoma. TMT is easy to assess and its measurement is consistent between evaluators.

Prospective evaluation of nasal septal perforation repair with absorbable plate and temporalis fascia in early adolescent patients.

OBJECTIVES: In the pediatric population, nasal septal perforations (NSP) are rare, and management is not well described. The use of various techniques has been reported in adults, including the use of interposition grafts, however this technique has not been described in the pediatric population. Our hypothesis is that the closure rate using absorbable d-lactide and l-lactide (each 50 %), polymer (PDLLA) plates as interposition grafts with temporalis fascia for NSP repair in the pediatric population will be an effective method compared to previous techniques. METHODS: Chart review was performed on patients who underwent NSP repair before June 2021, results were compared to a prospective evaluation of an interposition plate graft for repair at a tertiary care children's hospital. RESULTS: Fifteen patients via previous techniques and 5 patients via PDLLA and fascia graft were reviewed. Etiology of perforations included 45 % idiopathic, 25 % traumatic, and 15 % iatrogenic. In the previous techniques group, 10 were male, mean (median) age 14.4 years (15.2). Average size of NSP was 12.6 mm ± 6.6 mm (SD). 14/15 (93 %) patients had resolution of symptoms at 10-week follow-up, and 2/15 (13 %) required repeat repair. Five prospective patients were repaired with a PDLLA and fascia interposition graft, 4 were female, mean (median) age 14.6 years (Nassif and Scott, 2021 Feb 1) [14]. Average size of NSP was 11 mm ± 2.2 mm (SD). 100 % had resolution of symptoms at 10-week follow-up, 0 needed repeat surgery. No significant difference was found in size of NSP or in need for repeat procedure (p > 0.05) between the groups. CONCLUSION: Use of absorbable PDLLA interposition grafts with temporalis fascia for NSP repair in the pediatric population is effective at closing and resolving symptoms associated with NSP.

The relationship between prognosis and temporal muscle thickness in 102 patients with glioblastoma.

Temporal muscle thickness measured on 3D MRI has recently been linked to prognosis in glioblastoma patients and may serve as an independent prognostic indicator. This single-center study looked at temporal muscle thickness and prognosis in patients with primary glioblastoma. Overall survival was the major study outcome. For a retrospective analysis from 2010 to 2020, clinical data from 102 patients with glioblastoma at the Department of Oncology Radiotherapy of the First Affiliated Hospital of Dalian Medical University were gathered. Fifty-five cases from 2016 to 2020 contained glioblastoma molecular typing data, of which 45 were IDH wild-type glioblastomas and were analysed separately. TMT was measured on enhanced T1-weighted magnetic resonance images in patients with newly diagnosed glioblastoma.Overall patient survival (OS) was calculated by the Kaplan-Meier method and survival curves were plotted using the log-rank-sum test to determine differences between groups, and multifactorial analyses were performed using a Cox proportional-risk model.The median TMT for 102 patients was 6.775 mm (range: 4.95-10.45 mm). Patients were grouped according to median TMT, and the median overall survival (23.0 months) was significantly longer in the TMT > median group than in the TMT median group (P 0.001; Log-rank test). Analysing 45 patients with IDH wild type alone, the median overall survival (12 months) of patients in the TMT > median group was significantly longer than that of patients in the TMT ≤ median group (8 months) (P < 0.001; Log-rank test).TMT can serve as an independent prognostic factor for glioblastoma.

Reduced temporal muscle thickness predicts shorter survival in patients undergoing chronic subdural haematoma drainage.

BACKGROUND: Chronic subdural haematoma (CSDH) drainage is a common neurosurgical procedure. CSDHs cause excess mortality, which is exacerbated by frailty. Sarcopenia contributes to frailty - its key component, low muscle mass, can be assessed using cross-sectional imaging. We aimed to examine the prognostic role of temporal muscle thickness (TMT) measured from preoperative computed tomography head scans among patients undergoing surgical CSDH drainage. METHODS: We retrospectively identified all patients who underwent CSDH drainage within 1 year of February 2019. We measured their mean TMT from preoperative computed tomography scans, tested the reliability of these measurements, and evaluated their prognostic value for postoperative survival. RESULTS: One hundred and eighty-eight (122, 65% males) patients (median age 78 years, IQR 70-85 years) were included. Thirty-four (18%) patients died within 2 years, and 51 (27%) died at a median follow-up of 39 months (IQR 34-42 months). Intra- and inter-observer reliability of TMT measurements was good-to-excellent (ICC 0.85-0.97, P < 0.05). TMT decreased with age (Pearson's r = -0.38, P < 0.001). Females had lower TMT than males (P < 0.001). The optimal TMT cut-off values for predicting two-year survival were 4.475 mm for males and 3.125 mm for females. TMT below these cut-offs was associated with shorter survival in both univariate (HR 3.24, 95% CI 1.85-5.67) and multivariate (HR 1.86, 95% CI 1.02-3.36) analyses adjusted for age, ASA grade and bleed size. The effect of TMT on mortality was not mediated by age. CONCLUSIONS: In patients with CSDH, TMT measurements from preoperative imaging were reliable and contained prognostic information supplemental to previously known predictors of poor outcomes.

Bichectomy Surgery and EMG Masticatory Muscles Function in Adult Women: A Longitudinal Study.

AIM: This longitudinal study aimed to evaluate the electromyographic activity of the masseter and temporal muscles in adult women who underwent buccal fat removal. MATERIALS AND METHODS: The sample consisted of 20 healthy adult women with no temporomandibular dysfunction and normal occlusion, who were assessed before, 30, and 60 days after the surgery. The electromyographic signal of the masseter and temporal muscles was captured through mandibular tasks including rest, protrusion, right and left laterality, and maximum voluntary contraction with and without parafilm. The results obtained were tabulated and the Shapiro-Wilk normality test was performed, which indicated a normal distribution. Statistical analysis was performed using the repeated measures test (p < 0.05). RESULTS: Significant differences were observed between time periods in maximum voluntary contraction for the left masseter muscle (p = 0.006) and in maximum voluntary contraction with parafilm for the right temporal (p = 0.03) and left temporal (p = 0.03) muscles. CONCLUSION: Bichectomy surgery did not modify the electromyographic activity of the masseter and temporal muscles during the rest task but may have influenced variations in the electromyographic signal during different mandibular tasks after 60 days of surgery, suggesting compensatory adaptations and functional recovery. CLINICAL SIGNIFICANCE: Understanding the impact of buccal fat removal surgery on the stomatognathic system function provides insights into postoperative functional recovery and potential compensatory adaptations, guiding clinical management and rehabilitation strategies for patients undergoing such procedures. How to cite this article: Cardoso AHDLS, Palinkas M, Bettiol NB, et al. Bichectomy Surgery and EMG Masticatory Muscles Function in Adult Women: A Longitudinal Study. J Contemp Dent Pract 2024;25(3):207-212.

Revisiting the Use of Deep Temporalis Fascia Grafts in Ophthalmology.

PURPOSE: To report new indications for deep temporalis fascia (DTF) grafts in the ophthalmic field. METHODS: Monocentric retrospective interventional case series study. All the patients who underwent a DTF graft in an unpublished new indication over the study period (May 2020-October 2023) were included. For each patient, gender, age, graft indication, outcomes, complications, and follow-up duration were collected. In most cases, the DTF graft was covered by a vascularized flap. RESULTS: Eight patients underwent a DTF graft over the study period. The indications were: radiotherapy-induced scleral necrosis in three cases, tendinoplasty to replace the inferior rectus muscle tendon invaded by a locally advanced conjunctival carcinoma in one case, Ahmed glaucoma valve tube exposure in one case, intraocular lens with scleral fixation exposure in one case, orbital cerebrospinal fluid fistula (orbitorrhea) in one case, and post-traumatic complete corneal graft loss in one case. The DTF graft was successful in 87.5% of cases after a mean follow-up of 11.4 months. No complications were observed. CONCLUSIONS: DTF graft is a highly versatile graft that can be easily harvested. New indications for DTF grafts may include the repair of radiotherapy-induced scleral necrosis, the creation of oculomotor tendon and the temporary packing of large ocular tissue loss in an emergency context. Further studies with a longer follow-up are needed to confirm our preliminary results.

Free temporalis muscle fascia graft in dural reconstruction following surgical resection of intermediate and malignant skull base tumors: A 10-year experience from a single center.

BACKGROUND: Data from patients with post-ablative dural defects reconstructed using a free temporalis muscle fascia graft (FTFG) after resection of anterior or central skull base tumors were retrospectively analyzed. METHODS: The primary predictor and outcome variables were the reconstructive methods for dural repair and postoperative cerebrospinal fluid (CSF) leakage rate, respectively. RESULTS: Eighty patients were included, and 94 postoperative dural reconstructions were performed using FTFG. The postoperative CSF leakage rate was 3.19%. The postoperative CSF leakage rates did not significantly differ between open and endonasal endoscopic surgeries (1.92% vs. 4.88%; p > 0.05). In cases completed using the endonasal endoscopic approach, the postoperative CSF leakage rate was significantly associated with the intraoperative CSF leak flow (p < 0.05). CONCLUSIONS: Post-ablative dural defect reconstruction using FTFG resulted in low postoperative CSF leakage and complication rates comparable to those of free fascia lata graft from available literature.

Temporal Muscle Swelling after Clipping Surgery with Frontotemporal Craniotomy Is Associated with Immediate Postcraniotomy Headache.

Immediate postcraniotomy headache frequently occurs within the first 48 h after surgery. The mechanisms underlying immediate postcraniotomy headache are not yet fully understood, and effective treatments are not yet established. This study aimed to identify the factors associated with immediate postcraniotomy headache in patients who underwent clipping surgery with frontotemporal craniotomy and to examine the effects of these factors on postcraniotomy headache. A total of 51 patients were included in this study. Immediate postcraniotomy headache was defined as pain with numerical rating scale score ≥4 on postoperative day 7. Sixteen patients (31.4%) had immediate postcraniotomy headache. The headache-positive group had a higher incidence of preoperative analgesic use (50.0% vs. 5.7%, respectively, p < 0.001), increased temporal muscle swelling ratio (137.0%±30.2% vs. 112.5%±30.5%, respectively, p = 0.01), and higher postoperative analgesic use (12.9±5.8 vs. 6.7±5.2, respectively, p < 0.001) than the headache-negative group. The risk factors independently associated with immediate postcraniotomy headache were preoperative analgesic use and temporal muscle swelling by >115.15% compared with the contralateral side in the receiver operating characteristic analysis. Postcraniotomy headache was significantly more common in patients with preoperative analgesic use and temporal muscle swelling than in those without (p < 0.001 and p = 0.002, respectively). Altogether, patients with immediate postcraniotomy headache had greater preoperative analgesic use, greater temporal muscle swelling ratio, and higher postoperative analgesic use than those without. Thus, temporal muscle swelling is a key response to immediate postcraniotomy headache.

Immediate lengthening temporalis myoplasty for facial palsy reconstruction following facial nerve inclusive total parotidectomy.

Immediate lengthening temporalis myoplasty (Labbé procedure) for immediate dynamic facial reanimation after nerve-inclusive parotidectomy in the elderly population is undocumented in the literature. The aim of this work was to determine whether the Labbé approach could achieve immediate, good functional and static results in elderly patients with acquired facial palsy. A retrospective analysis of five patients with parotid malignancies involving the facial nerve who underwent parotidectomy and an immediate Labbé procedure was performed. The House-Brackmann and Sunnybrook scores for facial palsy were used as objective measurements of the functional outcome. All patients underwent total parotidectomy, neck dissection, Labbé procedure, immediate temporary tarsorrhaphy, brow lift, and postoperative radiotherapy. Mean patient age was 83 (range 73-87) years. The average resected tumour size was 3.54 cm. The mean duration of surgery was 324 min and length of hospital stay 4 days. All patients experienced an improvement in House-Brackmann of one grade postoperative (grade V to IV in four, grade VI to V in one); the Sunnybrook score improved by 31 points on average (mean preoperative 3.8 vs postoperative 34.8). An immediate Labbé procedure following ablative parotid malignancy resection is a reliable and safe reconstructive procedure in a carefully selected elderly population, providing acceptable immediate static and dynamic hemifacial mimetic function and eliminating an additional facial palsy correction procedure.

Did temporomandibular gap arthroplasty with temporalis interpositional flap improve function and pain in patients with end-stage joint disease? A 5-year retrospective follow-up.

The primary aim of this study was to investigate whether patients with end-stage temporomandibular joint (TMJ) disease treated with gap arthroplasty with temporalis interpositional flap (GAT) had improved maximal interincisal opening (MIO) and TMJ pain in a long-term perspective. All patients with severe osteoarthritis, or fibrous or bony ankyloses, and subjected to GAT between 2008 and 2015 were included. The criteria of treatment success were TMJ pain VAS score ≤4 and MIO ≥30 mm. Reoperation was considered as a failure. Forty-four patients (mean age 47 years) were included in this retrospective descriptive case series and followed up for up to 7 years (mean 4.5). Comorbidities were frequent (n = 34) and most commonly rheumatic disease (n = 17). The indications for surgery were ankylosis (n = 32) or severe osteoarthritis (n = 12). Of the 44 included patients, 84% (n = 37) had a history of earlier TMJ surgery. The preoperative mean values for TMJ pain and MIO (VAS 7 and 23 mm, respectively) changed significantly (p < 0.001) to postoperative means of VAS 3 and 34 mm, respecitvely. The success rate was 59% (n = 26). When compared with a previous 2-year follow-up, the success rate was found to have decreased over time (p = 0.0097). The rate of successful treatment outcome in terms of MIO alone was 82% (n = 36). The most common reason for treatment failure was residual pain. In conclusion, the success-rate after GAT did not show long-term stability and continued to drop over time in this patient cohort. TMJ pain seems to be the main reason for failure.

'What's in a name', a systematic review of the pterional craniotomy for aneurysm surgery and its many modifications with a proposal for simplified nomenclature.

BACKGROUND: The pterional or frontosphenotemporal craniotomy has stood the test of time and continues to be a commonly used method of managing a variety of neurosurgical pathology. Already described in the beginning of the twentieth century and perfected by Yasargil in the 1970s, it has seen many modifications. These modifications have been a normal evolution for most neurosurgeons, tailoring the craniotomy to the patients' specific anatomy and pathology. Nonetheless, an abundance of variations have appeared in the literature. METHODS: A search strategy was devised according to the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. To identify articles investigating the variations in the pterional approach, the following search terms were applied: (pterional OR minipterional OR supraorbital) AND (approach OR craniotomy OR technique). RESULTS: In total, 3552 articles were screened with 74 articles being read in full with 47 articles being included for review. Each article was examined according the name of the technique, temporalis dissection technique, craniotomy technique and approach. CONCLUSION: This systematic review gives an overview of the different techniques and modifications to the pterional craniotomy since it was initially described. We advocate for the use of a more standardised nomenclature that focuses on the target zone to simplify the management approach to supratentorial aneurysms.

Effects of Pterional and Osteoplastic Craniotomy on Temporalis Muscle and Calvarial Bone Graft Atrophy.

This study aims to compare the effects of osteoplastic craniotomy on temporalis muscle and bone graft atrophy in patients operated on with a pterional approach to the standard technique. Patients operated on for an intracranial aneurysm with a pterional approach between 2014 and 2018 were studied. Following the exclusion criteria, 36 patients were included in this retrospective study. Temporalis muscle volume and bone graft volume were calculated. The volumes were compared from preoperative and postoperative computed tomography images for temporalis muscle and from early and late postoperative computed tomography images for the bone graft. The osteoplastic craniotomy group (group I) had 17 patients, and the standard craniotomy group had 19 patients (group II). Temporalis muscle volume and bone graft volume decreased statistically significantly in group II after surgery. However, no significant volume difference was found in group I measurements. When compared with the standard technique, osteoplastic craniotomy reduces the likelihood of postoperative temporalis muscle and bone graft atrophy in patients undergoing pterional craniotomy. As a result, the patients' cosmetic and functional well-being is improved.

Automated temporalis muscle quantification and growth charts for children through adulthood.

Lean muscle mass (LMM) is an important aspect of human health. Temporalis muscle thickness is a promising LMM marker but has had limited utility due to its unknown normal growth trajectory and reference ranges and lack of standardized measurement. Here, we develop an automated deep learning pipeline to accurately measure temporalis muscle thickness (iTMT) from routine brain magnetic resonance imaging (MRI). We apply iTMT to 23,876 MRIs of healthy subjects, ages 4 through 35, and generate sex-specific iTMT normal growth charts with percentiles. We find that iTMT was associated with specific physiologic traits, including caloric intake, physical activity, sex hormone levels, and presence of malignancy. We validate iTMT across multiple demographic groups and in children with brain tumors and demonstrate feasibility for individualized longitudinal monitoring. The iTMT pipeline provides unprecedented insights into temporalis muscle growth during human development and enables the use of LMM tracking to inform clinical decision-making.

Quantitative analysis of facial symmetry and animation following intraoral orthodromic temporalis transfer in facial paralysis.

This study aimed to quantitatively analyze the degree and vector of commissure excursion following intraoral orthodromic temporalis transfer. Patients with unilateral facial paralysis who underwent intraoral temporalis transfer were included. Intra-oral coronoidectomy was followed by submucosa tunneling through two vertical intraoral incisions to fixate the temporalis tendon to the perioral location. Oral commissure excursion, upper lip and commissure height differences, and smile angle were measured. Postoperatively, the symmetry of commissure excursion improved in repose (affected side: 114.6 ± 7.0 mm, non-affected side: 115.2 ± 4.9 mm, p = 0.134), while asymmetry arose in smiling (affected side: 30.7 ± 3.4 mm, non-affected side: 34.5 ± 4.4 mm, p = 0.001). Furthermore, the postoperative smile angle demonstrated insufficient vertical movement on the affected side during smiling (affected side: 115.6 ± 5.8°, non-affected side: 118.4 ± 4.9°, p = 0.002) but no significant difference in repose (p = 0.134). Within the limitations of the study it seems that intraoral orthodromic temporalis transfer yields excellent resting symmetry, but smile asymmetry may occur owing to insufficient oral commissure excursion. Nevertheless, as a minimally invasive surgery, this technique can obviate visible scars and benefit patients wishing for the same and can have excellent resting symmetry.

Prognostic value of temporal muscle thickness, a novel radiographic marker of sarcopenia, in patients with brain tumor: A systematic review and meta-analysis.

Sarcopenia has been identified as a prognostic factor among certain types of cancer. However, it is unclear whether there is prognostic value of temporalis muscle thickness (TMT), a potential surrogate for sarcopenia, in adults patients with brain tumors. Therefore, we searched the Medline, Embase, and PubMed to systematically review and meta-analyze the relationship between TMT and overall survival, progression-free survival, and complications in patients with brain tumors and the hazard ratio (HR) or odds ratios (OR), and 95% confidence interval (CI) were evaluated. The quality in prognostic studies (QUIPS) instrument was employed to evaluate study quality. Nineteen studies involving 4570 patients with brain tumors were included for qualitative and quantitative analysis. Meta-analysis revealed thinner TMT was associated with poor overall survival (HR, 1.72; 95% CI, 1.45-2.04; P < 0.01) in patients with brain tumors. Sub-analyses showed that the association existed for both primary brain tumors (HR, 2.02; 95% CI, 1.55-2.63) and brain metastases (HR, 1.39; 95% CI, 1.30-1.49). Moreover, thinner TMT also was the independent predictor of progression-free survival in patients with primary brain tumors (HR, 2.88; 95% CI, 1.85-4.46; P < 0.01). Therefore, to improve clinical decision making it is important to integrate TMT assessment into routine clinical settings in patients with brain tumors.

Orbital exenteration reconstruction using a superficial temporalis muscle flap: The "Carpaccio flap", an innovative approach.

INTRODUCTION: Malignant orbital diseases may lead surgeons to practice an orbital exenteration associated with chemotherapy and/or radiotherapy to ensure curative treatment. That radical procedure makes physicians consider reconstructive filling in order to allow prothesis wearing and reduce esthetic and social after-effects. We first describe the clinical case of a 6-year-old patient who presented an orbital rhabdomyosarcoma and underwent an orbital exenteration with immediate reconstruction by a superficial temporal pedicled on the middle temporalis muscle flap. TECHNICAL NOTE: Through that case-report, we propose an original temporal flap to repair ipsilateral midface defects which may reduce donor site side effects and allow furthers corrections. DISCUSSION: In pediatrics cases, our Carpaccio flap was an available regional tool to rehabilitate an irradiated orbital socket with an appropriate bulking and vascularization effect after subtotal exenteration. Furthermore, we prescribe that flap as a posterior orbital filling, when eyelid and conjunctiva are spared, to prepare orbital prosthesis implementation. A mild sunken temporal fossa appears with our procedure but by preserving the deep layer of the temporalis muscle, autologous reconstruction such as lipofilling are permitted in post-radiotherapy condition to enhance esthetic sequelae.

Chronological Volume Changes of the Temporal Muscle Pedicle Used for Encephalo-myo-synangiosis in Combined Revascularization for Moyamoya Disease: A Prospective Observational Study.

Although postoperative neurological events due to brain compression by the swollen temporal muscle are a rare complication, the chronological volume changes of the temporal muscle pedicle and their clinical impact have not yet been documented. This prospective observational study aimed to investigate the chronological volume changes in the temporal muscle pedicle in Moyamoya disease (MMD). Eighteen consecutive combined revascularization procedures using the temporal muscle were performed for symptomatic MMD in 2021. The postoperative pedicle volume was quantified using repeated computed tomography images on postoperative days (PODs) 0, 1, 7, 14, and 30. Postoperative neurological events with radiological evaluations and collateral development evaluated using magnetic resonance angiography obtained 6 months after surgery were studied. On average, the postoperative temporal muscle pedicle volume was most significantly increased by as much as 112% ± 9.6% on POD 7 (P < 0.001) and decreased by as little as 52% ± 21% on POD 30 (P < 0.0001) relative to POD 0. One exceptional patient (overall incidence, 5.6%) demonstrated postoperative transient neurological events due to brain compression by the swollen temporal muscle with decreased focal cerebral blood flow in the adjacent cortical area. The postoperative collateral development via direct and indirect revascularizations was confirmed in 16 (89%) and 12 (67%) hemispheres, respectively. All patients, except for one rebleeding case, showed independent outcomes at the mean latest follow-up period on 290 ± 96 days after surgery. Our observations confirmed the temporal profile of muscle pedicle volume changes after combined revascularization. Through routine attempts to avoid the unfavorable effects of temporal muscle swelling, combined revascularization can provide favorable outcomes in symptomatic MMD.

Salvation of Temporalis Muscle in Cranioplasty: A Technique Note.

OBJECTIVE: The preservation of the temporalis muscle during cranioplasty is very important for postoperative masticatory function and aesthetics. The key technique for temporalis muscle preservation is to find the surgical plane during the operation. METHODS: In the past, the so-called antiadhesion method could not be used to find the surgical plane very well. Here, we describe a novel method for separating the temporalis muscle and dura through an illustrative case, utilizing the natural space of the temporalis muscle at the bony border attachment point. RESULTS: The temporalis muscle is stretched by a wire saw to find the surgical plane quickly and accurately, maximizing the preservation of the temporalis muscle without damaging the dura. CONCLUSIONS: The technical effect is ideal, the operation is simple, and the technique is suitable for promotion.

Long-term evaluation of masseter muscle activity, dimensions, and elasticity after orthognathic surgery in skeletal class III patients.

OBJECTIVE: To evaluate changes in the masseter muscle after orthognathic surgery using electromyography (EMG), ultrasonography (US), and ultrasound elastography (USE) in individuals with skeletal class III anomaly over long-term follow-up and compare with a control group. MATERIALS AND METHODS: The study group included 29 patients with class III dentofacial deformities scheduled to undergo orthodontic treatment and orthognathic surgery. The control group included 20 individuals with dental class I occlusion. Assessment of the masseter muscles using EMG, US, and USE was performed before orthognathic surgery (T1) and at postoperative 3 months (T2) and 1 year (T3) in the study group, and at a single time point in the control group. All assessments were performed at rest and during maximum clenching. Masseter muscle activity, dimension, and hardness were analyzed. RESULTS: Electromyographic activity of the masseter muscle during maximum clenching was increased at postoperative 1 year but did not reach control group values. On ultrasonography, the masseter muscle showed minimal changes in dimension at postoperative 1 year compared to preoperative values and remained below control group values. The postoperative increase in masseter muscle hardness at rest and during maximum clenching persisted at postoperative 1 year. CONCLUSION: The results of this study suggest that after orthognathic surgery, additional interventions and much longer follow-up are needed to ensure better muscle adaptation to the new occlusion and skeletal morphology. CLINICAL RELEVANCE: All assessment methods are useful for comprehensively evaluating changes in the masticatory muscles after orthognathic surgery.